The present invention relates to screen printing.
More particularly, the invention relates to an improved screen printing method and to apparatus for carrying this method into effect.
It is known to screen print with the aid of a flat stencil or printing screen which is arranged above the workpiece to be printed (e.g. a sheet material). A counter-pressure roller supports the printing screen (and the subjacent workpiece) from below, and a pair of squeegees are arranged above the screen and squeegee printing ink through the screen. A machine of this type is disclosed in U.S. Pat. No. 3,120,180 for printing onto discrete sheets of paper or the like. It is not suitable for printing onto continuous workpiece webs since the color interspaces between the pattern repeats must be very long, due to the fact that the dual squeegee device is stationary and is associated with the counter-pressure roller in such a manner that the squeegee which effects printing is located permanently directly above the upper apex line of the counter-pressure roller. The distance between the printing squeegee and the drag squeegee determines the spacing between the pattern repeats. It is evident that large distances between pattern repeats are a disadvantage where the printing of continuous webs is concerned since the web material which remains unprinted between the pattern repeats must be discarded as scrap.